Rotation sensor

Abstract

A rotation detecting sensor (A) is fixed to a sensor fixing member (7), through which it is fitted to a wheel support bearing assembly for detecting the rotation of a rotatable ring of the wheel support bearing assembly. A sensor unit (B) is made up of a sensor element ( 1 ) of a magnetic type for detecting an annular to-be-detected element of a rotatable ring, a cable ( 10 ) for feeding an output signal of the sensor element ( 1 ) to an outside, and a substrate ( 11 ) having an electroconductive segment ( 3 ) for electrically connecting an electrode ( 2 ) of the sensor element ( 1 ) with a core line ( 4 ) of the cable ( 10 ). This sensor unit (B) is fixed to the sensor fixing member ( 7 ) by means of the substrate ( 11 ). A molding portion ( 8 ) is provided around the sensor unit (B) and molded with a thermoplastic elastomer or a rubber material.

1 . A rotation detecting sensor fixed to a sensor fixing member, through which it is fitted to a wheel support bearing assembly, for detecting the rotation of a rotatable ring of the wheel support bearing assembly, which comprises:
 a sensor unit including a sensor element of a magnetic type provided in coaxial relation with the rotatable member for detecting a rotation of an annular to-be-detected element, a cable for feeding an output signal of the sensor element to an outside, and a substrate having the sensor element thereon and one end portion of the cable fitted thereto and further having an electroconductive segment for electrically connecting an electrode of the sensor element with a core line of the cable, the sensor unit being fixed to the sensor fixing member through the substrate; and   a molding portion provided around the sensor unit and molded with a thermoplastic elastomer or a rubber material,   in which a portion of the cable proximate to the substrate is fixed to the sensor fixing member by means of a clamp member provided in the sensor fixing member, in which case the molding portion covers the sensor unit so as to encompass a part of the clamp member.   
     
     
         2 . The rotation detecting device as claimed in  claim 1 , in which the molding is a molding accomplished by the use of a mold assembly. 
     
     
         3 . The rotation detecting device as claimed in  claim 2 , in which the mold assembly comprises upper and lower molds and the molding portion is molded by inserting the sensor unit and the thermoplastic elastomer or rubber material between the upper and lower molds and applying a pressure across the upper and lower molds while the latter are heated. 
     
     
         4 . The rotation detecting device as claimed in  claim 1 , in which the sensor element comprises a Hall element, a magnetoresistive effect element (MR element), a giant magnetoresistive effect element (GMR element) a tunnel magnetoresistive element (TMR element) or a coil. 
     
     
         5 . The rotation detecting device as claimed in  claim 1 , in which the sensor fixing member is fitted to a stationary ring of the wheel support bearing assembly or its peripheral member. 
     
     
         6 . The rotation detecting device as claimed in  claim 1 , in which the sensor fixing member concurrently serves as a covering for covering an end face of the wheel support bearing assembly. 
     
     
         7 . The rotation detecting device as claimed in  claim 1 , in which the molding is accomplished by means of an injection molding using the mold assembly by inserting the sensor unit into the mold assembly and subsequent injecting the thermoplastic elastomer into the mold assembly to form the molding portion by means of an injection molding. 
     
     
         8 . The rotation detecting device as claimed in  claim 1 , in which the molding is accomplished by means of an injection molding using the mold assembly by inserting the sensor unit into the mold assembly and subsequent injecting the rubber material into the mold assembly to form the molding portion by means of an injection molding. 
     
     
         9 . The rotation detecting device as claimed in  claim 1 , in which the mold assembly comprises an upper mold and a lower mold and the molding portion is molded by charging the sensor unit and the rubber material in one of the upper and lower molds and injection molding the rubber material from the other of the upper and lower molds.